双语有声阅读：镍钛合金

Nitinol

 

Nitinol is one of the most extraordinary metals to be discovered this century: A simple alloy¹ of nickel and titanium, nitinol has some perplexing properties. A metal with a memory, it can be made to remember any shape into which it is fashioned, returning to that shape whenever it is heated.

 

For example, a piece of nitinol wire bent² to form a circle that is then heated and quenched³ will remember this shape. It may then be bent or crumpled⁵, but on reheating, will violently untwist, reforming its original shape. This remarkable⁶ ability is called Shape Memory Effect (SME); other alloys⁷, such as brasses⁸, are known to possess it to a limited extent. No one fully⁹ understands SME,and nitinol remains¹⁰ particularly perplexing, for, whenever it performs this peculiar¹¹ feat¹², it appears to be breaking the laws of thermodynamics by springing back into shape with greater force than was used to deform¹³ it in the first place.

 

But not only is nitinol capable of remembering, it also has the ability to "learn". If the heating-cooling-crumpling-reheating process is carried out sufficiently¹⁴ often, and the metal is always crumpled in exactly the same way, the nitinol will not only remember its original shape, but gradually it learns to remember its crumpled form as well, and will begin to return to the same crumpled shape every time it is cooled. Eventually, the metal will crumple⁴ and uncrumple, totally unaided, in response to changes in temperature and without any sign of metal fatigue¹⁵.

 

Engineers have produced prototype engines that are driven by the force of nitinol springing from one shape to another as it alternately encounters hot and cold water. The energy from these remarkable engines is, however, not entirely¹⁶ free: heat energy is required to produce the temperature differences needed to run the engine. But the optimum temperatures at which the metal reacts can be controlled by altering the proportions of nickel to titanium; some alloys will even perform at room temperature. The necessary temperature range between the warm and the cold can be as little as twelve degrees centigrade.

 

镍钛合金

 

镍钛诺是这个世纪所发现的最不寻常的金属之一，作为镍和钛的简单的一种合金，镍钛诺具有一些令人惊叹的特征。 这是一种有记忆力的金属，人们可以使它记住它被塑成的任何形状，并在加热后恢复这一形状。 比如，一节镍钛诺线圈在加热冷却后会记住圆圈这形状。 随后它可能被弯折成其它形状，但一旦再次加热，就会迅速地自动恢复成最初的圆圈状。 这种不寻常的能力被称为形状记忆效果(SME)。 其它一些合金如黄铜在一定程度上也具有这种特性。 目前人们对 SME 这一特性尚缺乏透彻的认识，而镍钛诺尤其使人惊奇，因为每当它展现这一惊人的功能时，似乎都违背了热力学原理。 因为它在恢复原有形状时所释放的力比人们使它变形所施加的力大得多。 镍钛诺不仅有记忆力，还能"学习"。如果加热-冷却-弯曲-再加热这一过程重复一定次数，且每次冷却后它都被丝毫不差地弯成同一形状，它不仅可以记住最初的形状，还能逐渐记住它被弯成的形状，并开始在每次冷却时恢复这一形状。

 

最终，它会自动地随温度变化而弯曲和恢复这些形状，并且没有任何疲劳迹象。 工程师们已制造出一些发动机样机，利用镍钛合金在交替遇热水和冷水时迅速改变形状所产生的力做推动力。 然而这些神奇的发动机工作时并非完全不耗能，因为必须有热能来制造温差才能使机器运转。 但人们可以通过改变合金中镍钛的比例来控制使它反应的最佳温度。 有的镍钛合金甚至能在室温下做出反应，冷暖之间的最小温差只有 12℃。

1 alloy   

n.合金，(金属的)成色

参考例句：

• The company produces titanium alloy.该公司生产钛合金。
• Bronze is an alloy of copper and tin.青铜是铜和锡的合金。

2 bent   

n.爱好，癖好；adj.弯的；决心的，一心的

参考例句：

• He was fully bent upon the project.他一心扑在这项计划上。
• We bent over backward to help them.我们尽了最大努力帮助他们。

3 quenched   

解（渴）( quench的过去式和过去分词 )； 终止（某事物）； （用水）扑灭（火焰等）； 将（热物体）放入水中急速冷却

参考例句：

• He quenched his thirst with a long drink of cold water. 他喝了好多冷水解渴。
• I quenched my thirst with a glass of cold beer. 我喝了一杯冰啤酒解渴。

4 crumple   

v.把...弄皱，满是皱痕，压碎，崩溃

参考例句：

• Take care not to crumple your dress by packing it carelessly.当心不要因收放粗心压纵你的衣服。
• The wall was likely to crumple up at any time.墙随时可能坍掉。

5 crumpled   

adj. 弯扭的, 变皱的 动词crumple的过去式和过去分词形式

参考例句：

• She crumpled the letter up into a ball and threw it on the fire. 她把那封信揉成一团扔进了火里。
• She flattened out the crumpled letter on the desk. 她在写字台上把皱巴巴的信展平。

6 remarkable   

adj.显著的，异常的，非凡的，值得注意的

参考例句：

• She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
• These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。

7 alloys   

n.合金( alloy的名词复数 )

参考例句：

• This is essentially a development of thoria dispersion strengthened nickel alloys. 这基本上是用二氧化钍弥散强度化的镍基合金。 来自辞典例句
• The lack of deep hardening in these alloys negates their use. 这些合金缺乏深层硬化能力使它们无法利用。 来自辞典例句

8 brasses   

n.黄铜( brass的名词复数 )；铜管乐器；钱；黄铜饰品（尤指马挽具上的黄铜圆片）

参考例句：

• The brasses need to be cleaned. 这些黄铜器要擦一擦。 来自辞典例句
• There are the usual strings, woodwinds, brasses and percussions of western orchestra. 有西洋管弦乐队常见的弦乐器，木管和铜管乐器，还有打击乐器。 来自互联网

9 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

10 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

11 peculiar   

adj.古怪的，异常的；特殊的，特有的

参考例句：

• He walks in a peculiar fashion.他走路的样子很奇特。
• He looked at me with a very peculiar expression.他用一种很奇怪的表情看着我。

12 feat   

n.功绩；武艺，技艺；adj.灵巧的，漂亮的，合适的

参考例句：

• Man's first landing on the moon was a feat of great daring.人类首次登月是一个勇敢的壮举。
• He received a medal for his heroic feat.他因其英雄业绩而获得一枚勋章。

13 deform   

vt.损坏…的形状；使变形，使变丑；vi.变形

参考例句：

• Shoes that are too tight deform the feet.(穿)太紧的鞋子会使脚变形。
• Ice crystals begin to deform measurably.冰晶就产生某种程度的变形了。

14 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

15 fatigue   

n.疲劳，劳累

参考例句：

• The old lady can't bear the fatigue of a long journey.这位老妇人不能忍受长途旅行的疲劳。
• I have got over my weakness and fatigue.我已从虚弱和疲劳中恢复过来了。

16 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。